Current: The amount of current is the same through any component in a series circuit. Voltage: The supply voltage in a series circuit is equal to the sum of. As mentioned in the previous section of Lesson 4, two or more electrical devices in a circuit can be connected by series connections or by parallel connections. Understanding it is crucial for beginners, electronics students, and anyone working with electrical systems. In this article, we'll explain what a series circuit is, how to draw a series circuit diagram, calculate. In a series circuit, all components are connected end-to-end to form a single path for current flow.